1. Field of the Invention
This invention relates to means for launching a remotely piloted aircraft. More specifically, the invention is directed toward a structure for revolving the remotely piloted aircraft about a fixed axis in a plane that is inclined obliquely to the local gravitational field of the launch site.
2. Description of the Prior Art
The basic concept of launching an aircraft by attaching it to a structure which revolves about a fixed axis and subsequently releasing it from the structure is well known in the art. The apparatus utilized by these prior art teachings revolves the aircraft in a circular path having a vertical or horizontal axis, and is generally cumbersome and complex. Among the disadvantages of the prior art devices are that the aircraft is typically attached to the launch apparatus at the wing tip, which causes high acceleration loads along the wing spar in a direction perpendicular to the aircraft fuselage. This requires the aircraft to have structure which increases its strength to enable launching, but which is totally unnecessary during flight. Obviously, such structure increases aircraft weight and decreases aircraft payload. Additionally, when the launching apparatus and the aircraft are at rest, the aircraft is suspended so far above the ground as to make routine maintenance and servicing difficult, if not impossible. The prior art launching devices that have a horizontal axis and revolve in a vertical plane require complex supporting devices at each end of the axis in order to avoid large cantilevered loads. in this type of launch device, the aircraft is usually supported by its fuselage such that its wing span is parallel to the axis of the axle, which further requires that the supporting structures be separated by a greater distance to avoid collision with the aircraft. This, in turn, necessitates a relatively large area in which to erect and maintain the launch device.
Those prior art devices which utilize rigid arms supporting the aircraft are also subject to severe stress due to the vibration caused by rotation of the unbalanced arm during the launch. If counterweights are provided to offset the weight of the aircraft, the structure still suffers vibration stress when the aircraft is released due to the imbalance generated by the counterweight. These factors require the prior art launch devices to have complex and cumbersome support structures to provide the necessary rigidity.